The present invention pertains to a hydro-mechanical drive system for a combine harvester or similar agricultural vehicle. More particularly, the invention pertains to a hydro-mechanical drive system for a combine harvester that integrates the hydraulic reel drive system into the main hydraulic system to provide a single hydro-mechanical drive system for activating and operating, (i.e., driving, positioning, powering and/or controlling), the steering mechanism, header height controlling apparatus, reel positioning systems, and the reel drive system.
In the art of mechanically harvesting crops, it is known that a harvesting vehicle, such as a combine harvester, is used to optimize crop harvesting efficiency. The combine harvester is typically a self-propelled motorized device having a motor and a combine hydro-mechanical main drive system for operationally engaging a steering mechanism, a transmission, and a header height controlling apparatus. One such combine hydro-mechanical main drive system for an agricultural vehicle is disclosed in U.S. Pat. No. 6,247,295 to Hansen et al., which is incorporated herein in its entirety by reference.
The header height controlling apparatus is a device for hydraulically controlling the height and position of a header, wherein the header is that part of the combine harvester that cuts the crop being harvested. The header height controlling apparatus usually comprises several hydraulic cylinders that hydraulically lift or lower the header in response to commands from an on board microcomputer. The header typically includes a frame, a reel assembly for pulling crops into a cutting portion or sickle assembly, a cutting portion or sickle assembly for cutting the crops, and an auger assembly for carrying the cut crop into elevator assembly or collecting chute. The reel assembly generally includes a reel supported on reel support arms, a hydraulic reel lift system comprising hydraulic cylinders for moving the reel support arms to move the reel into position when needed, and a hydraulic reel drive system for rotating the reel when in operation. One example of a header including a reel assembly is disclosed in U.S. Pat. No. 4,487,004 to Kejr, which is herein incorporated by reference in its entirety. In Kejr, the reel lift system and the reel drive system are respectively two independent hydraulic drive systems, which are separate and distinct from any main hydraulic drive system for operating components of the combine harvester, such as the steering mechanism.
In the combine harvesters of the prior art, the combine header system, the steering hydro mechanical system, system and the reel assembly hydro-mechanical drive system are separate and distinct hydraulic systems. Consequently, two or more separate hydraulic systems are built into the combine harvester during manufacture, which creates several drawbacks. First, by having multiple separate hydraulic systems, the construction of each vehicle is complicated by more parts required and more assembly steps needed during manufacture. Second, having multiple separate hydraulic systems demands more complicated and rigorous maintenance regimes once manufacturing is complete. Lastly, because each hydraulic system takes power from the vehicle engine during operation, this power drain on the engine results in higher fuel consumption and higher operating costs for the vehicle. In addition, frequently, the reel assembly is operationally disengaged, or turned off, because the particular crop being harvested does not require the operation of the reel to harvest. In these cases, valuable engine power is still expended to maintain pressures in the hydraulic reel assembly drive system, despite the fact that the reel is not performing any function.
Consequently, there is a need for an integrated combine reel drive system that operates both the combine main drive system and the reel assembly drive system, and which is constructed to conserve energy during harvesting operations whenever the reel assembly is not engaged to facilitate harvesting. The present invention endeavors to satisfy this need by providing an integrated combine reel drive system that overcomes the drawbacks of the prior art machines.
Accordingly, a primary object of the invention is to overcome the disadvantages of the prior art mechanical harvesting machines.
Another object of the present invention is to provide a mechanical harvesting machine with an integrated combine reel drive system that is practical and cost effective to manufacture.
Another object of the present invention is to provide a mechanical harvesting machine with an integrated combine reel drive system that is durable, reliable, and easy to maintain.
Another object of the present invention is to provide a mechanical harvesting machine with an integrated combine reel drive system that improves overall combine power efficiency, thereby decreasing engine fuel consumption and operating costs.
In accordance with the stated objectives, the present invention provides an integrated combine reel drive system and a mechanical harvesting machine that includes the integrated combine reel drive system, wherein the integrated combine reel drive system is a hydraulic or hydro-mechanical drive system for operating both the header and steering mechanisms of a harvester combine, and the reel assembly drive system that operates the reel of the header. Specifically, the integrated combine reel hydro-mechanical drive system of the present invention is a single integrated hydraulic circuit containing a hydraulic fluid and including a hydraulic reservoir, wherein the single hydraulic circuit includes a hydraulic header circuit connected to the reservoir and supplying hydraulic fluid to activate a header implement, a steering mechanism for the harvesting machine, and a reel of the header implement; and a variable pump connected to the reservoir and disposed in the single circuit to pump hydraulic fluid to the header circuit.
Further objects, features and advantages of the present invention will become apparent from the Detailed Description of Preferred Embodiments which follows, when considered together with the attached drawings.